feat(application): add PlayMove command and handler

src/Chess/Application/Command/PlayMove/PlayMoveCommand.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Chess\Application\Command\PlayMove;
+
+final class PlayMoveCommand
+{
+    public function __construct(
+        public readonly string $gameId,
+        public readonly string $from,
+        public readonly string $to,
+    ) {
+    }
+}

src/Chess/Application/Command/PlayMove/PlayMoveHandler.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Chess\Application\Command\PlayMove;
+
+use Chess\Domain\Repository\GameRepositoryInterface;
+use Chess\Domain\Service\MoveValidator;
+use Chess\Domain\Value\GameId;
+use Chess\Domain\Value\Move;
+use Symfony\Component\Messenger\Attribute\AsMessageHandler;
+
+#[AsMessageHandler(bus: 'command.bus')]
+final class PlayMoveHandler
+{
+    public function __construct(
+        private readonly GameRepositoryInterface $repository,
+        private readonly MoveValidator $validator,
+    ) {
+    }
+
+    public function __invoke(PlayMoveCommand $command): void
+    {
+        $game = $this->repository->findById(GameId::fromString($command->gameId));
+
+        if (null === $game) {
+            throw new \DomainException(\sprintf('Game "%s" not found.', $command->gameId));
+        }
+
+        $game->play(Move::fromString($command->from, $command->to), $this->validator);
+        $this->repository->save($game);
+    }
+}

tests/Chess/Application/PlayMove/PlayMoveHandlerTest.php

@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Chess\Tests\Application\Command\PlayMove;
+
+use Chess\Application\Command\PlayMove\PlayMoveCommand;
+use Chess\Application\Command\PlayMove\PlayMoveHandler;
+use Chess\Domain\Model\Game;
+use Chess\Domain\Repository\GameRepositoryInterface;
+use Chess\Domain\Service\MoveValidator;
+use Chess\Domain\Value\Color;
+use Chess\Domain\Value\GameId;
+use PHPUnit\Framework\TestCase;
+
+final class PlayMoveHandlerTest extends TestCase
+{
+    public function testItPlaysAMoveOnAnExistingGame(): void
+    {
+        $game = Game::start();
+
+        $repository = new class($game) implements GameRepositoryInterface {
+            public ?Game $savedGame = null;
+
+            public function __construct(private readonly Game $game)
+            {
+            }
+
+            public function save(Game $game): void
+            {
+                $this->savedGame = $game;
+            }
+
+            public function findById(GameId $id): Game
+            {
+                return $this->game;
+            }
+        };
+
+        $handler = new PlayMoveHandler($repository, new MoveValidator());
+        $handler(new PlayMoveCommand($game->id()->toString(), 'e2', 'e4'));
+
+        self::assertNotNull($repository->savedGame);
+        self::assertSame(Color::Black, $repository->savedGame->currentTurn());
+    }
+
+    public function testItThrowsWhenGameNotFound(): void
+    {
+        $repository = new class implements GameRepositoryInterface {
+            public function save(Game $game): void
+            {
+            }
+
+            public function findById(GameId $id): ?Game
+            {
+                return null;
+            }
+        };
+
+        $this->expectException(\DomainException::class);
+
+        $handler = new PlayMoveHandler($repository, new MoveValidator());
+        $handler(new PlayMoveCommand('unknown-id', 'e2', 'e4'));
+    }
+}